The structure of current parallel robots comprises a base platform, a movable platform (also called as moving platform, as in the context hereafter), and derivative chains connected between the base platform and the movable platform.
Most existing parallel robots each have only one base platform, one movable platform and a group of derivative chains connected between the base platform and the movable platform. Such example includes handling (assembling) parallel robots and parallel machine tool robots. Both types of robots have the following defects: for handling (or assembling) parallel robots, one robot can only assemble components for one machine or equipment; and for parallel machine tool robots, one parallel machine tool robot can machine only one component at a time, but cannot conduct the same or substantially the same operation to two or more objects at the same time.
Some existing parallel robots also include parallel robots having two movable platforms. For example, patent reference CN 201320207661 discloses a parallel robot comprising two movable platforms and two groups of derivative chains, as well as two sets of corresponding driving and controlling systems which are independent from each other. Defects of this robot are that one object is manipulated by actuators on the two movable platforms and that it has a relatively complex structure. This robot cannot conduct the same or substantially the same operation to two or more objects at the same time.
There are also some walking parallel robots each comprising two parallel mechanisms and two movable platforms. Embodiments of them include walking parallel robots disclosed in patent reference CN 201010292424.1 and patent reference CN 03826959.7. Such a robot has two movable platforms and two groups of derivative chains, the structure of it comprises two parallel mechanisms which are independent from each other. Correspondingly, it comprises two sets of driving and controlling systems which are independent from each other. Walking action is achieved by means of the cooperation of two movable platforms (foot arches) which are independent from each other. A defect of such a robot is that the two movable platforms (foot arches) are equipped with two sets of driving and controlling systems which are independent from each other. The robot cannot be operated by only one set of driving and controlling system. The two independent parallel mechanisms can only walk or operate on one plane, but cannot walk on an opposite plane. In other words, if the robot is turned over by 180 degrees, it cannot walk. That is, the robot cannot conduct the same or substantially the same operation in two orientations.
Thus, a common defect in current parallel robots exists in that they do not comprise two or more movable platforms defined below: the movable platforms are associated with each other and possess certain symmetry, and they can fulfill the same or substantially the same operation or task by means of only one set of driving and controlling system.
An object of the invention is to overcome the above defect by providing a multiple-movable-platform parallel robot which comprises two or more movable platforms, the movable platforms possessing a certain symmetry therebetween and being able to conduct the same or substantially the same operation by means of only one set of driving system. In other words, the parallel robot comprises two or more movable platforms having the same or similar motion pattern. Meanwhile, the invention also provides a double-sided walking parallel robot which is also able to walk after it is turned over by 180 degrees, as well as a profiling or scaling type parallel robot.